JavaScript String - Exercises, Practice, Solution

Last update on May 06 2017 06:54:52 (UTC/GMT +8 hours)

JavaScript String [49 exercises with solution]

[An editor is available at the bottom of the page to write and execute the scripts.]

1. Write a JavaScript function to check whether an `input` is a string or not. Go to the editorTest Data :
console.log(is_string('w3resource'));
true
console.log(is_string([1, 2, 4, 0]));
falseClick me to see the solution

9. Write a JavaScript function to capitalize the first letter of each word in a string. Go to the editorTest Data :
console.log(capitalize_Words('js string exercises'));
"Js String Exercises"Click me to see the solution.

10. Write a JavaScript function that takes a string which has lower and upper case letters as a parameter and converts upper case letters to lower case, and lower case letters to upper case. Go to the editorTest Data :
console.log(swapcase('AaBbc'));
"aAbBC"Click me to see the solution.

11. Write a JavaScript function to convert a string into camel case.Go to the editorTest Data :
console.log(camelize("JavaScript Exercises"));
console.log(camelize("JavaScript exercises"));
console.log(camelize("JavaScriptExercises"));
"JavaScriptExercises"
"JavaScriptExercises"
"JavaScriptExercises"Click me to see the solution.

13. Write a JavaScript function to concatenates a given string n times (default is 1). Go to the editorTest Data :
console.log(repeat('Ha!'));
console.log(repeat('Ha!',2));
console.log(repeat('Ha!',3));
"Ha!"
"Ha!Ha!"
"Ha!Ha!Ha!"Click me to see the solution.

14. Write a JavaScript function to insert a string within a string at a particular position (default is 1).Go to the editorTest Data :
console.log(insert('We are doing some exercises.'));
console.log(insert('We are doing some exercises.','JavaScript '));
console.log(insert('We are doing some exercises.','JavaScript ',18));
"We are doing some exercises."
"JavaScript We are doing some exercises."
"We are doing some JavaScript exercises."Click me to see the solution.

15. Write a JavaScript function to humanized number (Formats a number to a human-readable string.) with the correct suffix such as 1st, 2nd, 3rd or 4th. Go to the editorTest Data :
console.log(humanize_format());
console.log(humanize_format(1));
console.log(humanize_format(8));
console.log(humanize_format(301));
console.log(humanize_format(402));
"1st"
"8th"
"301st"
"402nd"Click me to see the solution.

16. Write a JavaScript function to truncates a string if it is longer than the specified number of characters. Truncated strings will end with a translatable ellipsis sequence ("…") (by default) or specified characters. Go to the editorTest Data :
console.log(text_truncate('We are doing JS string exercises.'))
console.log(text_truncate('We are doing JS string exercises.',19))
console.log(text_truncate('We are doing JS string exercises.',15,'!!'))
"We are doing JS string exercises."
"We are doing JS ..."
"We are doing !!"Click me to see the solution.

17. Write a JavaScript function to chop a string into chunks of a given length. Go to the editorTest Data :
console.log(string_chop('w3resource'));
console.log(string_chop('w3resource',2));
console.log(string_chop('w3resource',3));
["w3resource"]
["w3", "re", "so", "ur", "ce"]
["w3r", "eso", "urc", "e"]Click me to see the solution.

18. Write a JavaScript function to count the occurrence of a substring in a string. Go to the editorTest Data :
console.log(count("The quick brown fox jumps over the lazy dog", 'the'));
Output :
2
console.log(count("The quick brown fox jumps over the lazy dog", 'fox',false));
Output :
1Click me to see the solution.

20. Write a JavaScript function that can pad (left, right) a string to get to a determined length. Go to the editorTest Data :
console.log(formatted_string('0000',123,'l'));
console.log(formatted_string('00000000',123,''));
Output :
"0123" "12300000"Click me to see the solution.

21. Write a JavaScript function to repeat a string a specified times. Go to the editorTest Data :
console.log(repeat_string('a', 4));
console.log(repeat_string('a'));
Output :
"aaaa"
"Error in string or count."Click me to see the solution.

22. Write a JavaScript function to get a part of a string after a specified character.Go to the editorTest Data :
console.log(subStrAfterChars('w3resource: JavaScript Exercises', ':','a'));
console.log(subStrAfterChars('w3resource: JavaScript Exercises', 'E','b'));
Output :
"w3resource" "xercises"Click me to see the solution.

24. Write a JavaScript function to truncate a string to a certain number of words. Go to the editorTest Data :
console.log(truncate('The quick brown fox jumps over the lazy dog', 4));
Output :
"The quick brown fox"Click me to see the solution.

25. Write a JavaScript function to alphabetize a given string. Go to the editor
Alphabetize string : An individual string can be alphabetized. This rearranges the letters so they are sorted A to Z.Test Data :
console.log(alphabetize_string('United States'));
Output :
"SUadeeinsttt"Click me to see the solution.

26. Write a JavaScript function to remove the first occurrence of a given 'search string' from a string. Go to the editorTest Data :
console.log(remove_first_occurrence("The quick brown fox jumps over the lazy dog", 'the'));
Output :
"The quick brown fox jumps over lazy dog"Click me to see the solution.

34. Write a JavaScript function to convert a string to title case. Go to the editorTest Data :
console.log(sentenceCase('PHP exercises. python exercises.'));
"Php Exercises. Python Exercises."Click me to see the solution.

35. Write a JavaScript function to remove HTML/XML tags from string. Go to the editorTest Data :
console.log(strip_html_tags('<p><strong><em>PHP Exercises</em></strong></p>'));
"PHP Exercises"Click me to see the solution.

40. Write a JavaScript function to Uncapitalize the first letter of each word of a string. Go to the editorTest Data :
console.log(unCapitalize_Words('Js String Exercises'));
"js string exercises"Click me to see the solution.

43. Write a JavaScript function to test whether the character at the provided (character) index is upper case. Go to the editorTest Data :
console.log(isUpperCaseAt('Js STRING EXERCISES', 1));
falseClick me to see the solution.

44. Write a JavaScript function to test whether the character at the provided (character) index is lower case. Go to the editorTest Data :
console.log(isLowerCaseAt ('Js STRING EXERCISES', 1));
trueClick me to see the solution.

45. Write a JavaScript function to get humanized number with the correct suffix such as 1st, 2nd, 3rd or 4th. Go to the editorTest Data :
console.log(humanize(1));
console.log(humanize(20));
console.log(humanize(302));
"1st"
"20th"
"302nd"Click me to see the solution.

48. Write a JavaScript function to get the successor of a string. Go to the editor

Note: The successor is calculated by incrementing characters starting from the rightmost alphanumeric (or the rightmost character if there are no alphanumerics) in the
string. Incrementing a digit always results in another digit, and incrementing a letter results in another letter of the same case. If the increment generates a carry, the character to the left of it is incremented. This process repeats until there is no carry, adding an additional character if necessary.Example :
string.successor("abcd") == "abce"
string.successor("THX1138") == "THX1139"
string.successor("<
>") == "<
>"
string.successor("1999zzz") == "2000aaa"
string.successor("ZZZ9999") == "AAAA0000"

49. Write a JavaScript function to get unique guid (an acronym for 'Globally Unique Identifier?) of the specified length, or 32 by default. Go to the editorTest Data :
console.log(guid());
console.log(guid(15));
"hRYilcoV7ajokxsYFl1dba41AyE0rUQR"
"b7pwBqrZwqaDrex"Click me to see the solution.

More to Come !

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